Hot answers tagged

15

The reason I would connect the positive cable first (in a negatively-earthed car) is that while tightening the positive connector with a spanner (wrench), if I were to touch the body of the car with the spanner at the same time, nothing would happen and I would be OK. However if the negative was already connected to the battery and I shorted the positive to ...


12

tl dr: Corrosion (once cleaned) is not a huge issue. It is just typical corrosion on the battery terminal. See this image: (NOTE: This is a 6V battery, but the same principles apply.) The blueish color you see is hydrated copper sulfate. When acid vapors escape from the battery, it can cause a reaction with any copper which may be in the terminal. The ...


10

This step is a carryover from days gone by and is not needed in modern vehicles. Batteries from 50 or 60+ years ago were not as powerful or reliable as modern ones. Older batteries had difficulty handling the load of the starter motor alone. Engines cranked longer before starting and were cranking large displacement engines. Any added load from wiper, radio ...


9

The starter circuit should only draw whatever current it needs so the excess shouldn't cause any problem.


8

The Voltage levels let you know how much charge is present in the battery thus warning you before the entire thing drains out. For example the below information is for the standard car battery which starts the car, works the steoreo etc , not the additional equipments like on the ambulance. 12.66v . . . 100% Charge 12.45v . . . 75% 12.24v . . . 50% ...


8

Since you have a battery which isn't that old (most batteries have about a five year life span), I'd suggest you put it on a charger and try to recharge it. This will allow the battery to come back to full charge without putting an undue stress on your alternator. You have to decide if the time spent in recharging the battery is worth your time. To me, ...


8

I think you have an issue with the way you are thinking. You are describing the issue as if the batteries are hooked up in series. In that case, yes there'd be a huge back current going on. Both batteries would be made into a complete circuit and you'd have global thermal nuclear meltdown (or whatever the car battery equivalent would be). This is not the ...


7

It says right on the webpage: Conventional all-wheel drive cars employ complex mechanical linkages to distribute power from a single engine to all four wheels. This sacrifices efficiency in favor of all weather traction. In contrast, each Model S motor is lighter, smaller and more efficient than its rear wheel drive counterpart, providing both improved ...


7

I don't know the actual justification, but to me it makes sense to always attach positive first because it is easy to accidentally touch the lead to something else while installing. If the negative lead were already attached, then touching the positive lead to just about anything on the car that is metal would short out the battery.


7

The question really is what the voltage was just before the jump start. A jump start is nothing more than get the engine running from another battery. If the engine runs again, the alternator/dynamo will charge the partly depleted battery again. Nobody can tell how long you need to drive to get the battery fully loaded again, as this depends on the state of ...


7

Two reasons: To reduce the possibility of short-circuiting the battery by removing the connection to 'ground' To make sure everything is switched off and unable to function while you're working on it. You don't want, for example, the electric fan to suddenly kick in while you've got your hands in there...


7

The two biggest disadvantage of lead acid batteries compared to the newer types like Li Ion are that they are heavier, and that they contain liquid acid. Another possible issue is that they can produce hydrogen gas. On the other hand, they are very inexpensive, have a long life expectancy, have a very high tolerance for overcharging without being damaged, ...


7

No. Your 12V socket is designed to deliver 12V, at a current described in your car manual. Most of my 12V sockets in the car can deliver up to 5A apparently (haven't tested this though, but I run a 200W invertor when I go car-camping. It is handy for everything) The worst that can happen is if your invertor tries to draw more than the 12V socket is fused ...


7

An insufficiently-charged battery would explain what you're seeing: the unresponsive throttle is because the throttle is electronically-actuated (at least that's what eBay reckons) Not sure about the Sentra, but airbag and engine oil lights can turn on due to insufficient voltage the engine will stall because the fuel injectors need electricity to ...


7

Yes, as everyone is stating, a spark igniting hydrogen gas could cause an explosion, causing injury from small parts, sulfuric acid or both. Very nasty. Hydrogen gas is a byproduct of electrical energy created from a chemical reaction of lead plates submerged into the acid and water. Sparks can happen internally, too. Like when the lead plates warp from ...


7

Repeated clicking is a result of not enough power making it to the starter. Your battery either has a bad connection, or is too weak to turn the starter motor. Battery Connection Your problem may be entirely due to a bad connection. Starters draw a lot of amps, and batteries are weaker in cold temperatures. I'd start by fully exposing the terminals. You ...


7

The fastest, cheapest and easiest solution is to add a battery disconnect switch to the car. After placing the ignition switch into acc mode the open the hood and disconnect the switch. When you arrive at your destination, open the hood and reconnect the switch. This costs under $20. It also eliminates the need to run anything or calculate anything. Many ...


6

The amp count tells you the maximum amount of current that the equipment can supply. Eg. Your car needs 600 amps to start: The 1000 amp jumper can handle it. Your car needs 1200 amps: The 1000 amp jumper can't do it. You'll have to find a bigger one. Be aware that this does not apply to voltage. If you have a 6V battery and you connect it to a 12V ...


6

You should not incur any issues using a secondary battery with a battery isolator. It will not cause any damage to your alternator. For your edification, it won't be using wasted energy, but your engine will probably using a tad more gas to operate the alternator, which will have to do more work. On a side note, you might want to rethink exactly what you ...


6

I don't think you are likely to "put undue stress on the alternator." It is a myth in my opinion that alternators can't handle charging a battery, Alternators are literally motors run in reverse and are designed to handle a lot of current. The only issue with charging a batter is it will get a bit warmer than usual and that shouldn't effect it as long as it ...


6

Lead sulfate crystals form on the battery plates as the battery discharges. As the battery becomes more discharged the crystals go from being soft and fluffy to much harder. Recharged in time, the lead sulfate is converted back into sulfuric acid and lead. A month is entirely too long for a battery to remain discharged. Reversing a serious sulfation ...


6

If there is nothing connected to it (which can draw power), no power will be drawn. To me that means there are no drawbacks. I would not have an issue of making the socket as always hot for just the purpose you suggest. NOTE: I don't know what else I can add here.


6

This could be caused by multiple things, the most likely case would be a bad battery in need of replacement. However before coming to that conclusion there are a few things which can be checked. Make sure your battery terminals are in good working order and are not grounding out any where make sure they are insulated and not cracked and touching metal. ...


6

Yes its possible to start a car with Ultra capacitors.These caps dont appear to have a cycle life like the traditional lead acid battery does .The ability of these caps to provide starting current is very good .There are a couple of snags :The caps at present are more pricey than the best lead acid batteries.The caps are strung in series to get the nominal ...


6

I recommend you carry out the following steps: Have the starter relay tested. From the description provided (old starter was clicking) this may actually be fine but it is so easy to verify that it works it would be silly to not rule this out as the source of the problem. After locating the starter relay, have someone turn the key in the ignition to start ...


5

Conventional lead acid batteries produce hydrogen gas as a byproduct of the charging process. This gas tends to collect in and around the battery. As you are aware making the final connection can generate a substantial spark. By making the frame connection the point where the spark occurs it is far enough from the hydrogen gas to avoid an explosion.


5

Gloves are not essential, but highly recommended When replacing a car battery there are three potential hazards that relate to safety: electrical hazard - the battery is capable of generating 100's of amps' worth of current. You want to avoid shorting the two terminals with something like a wrench, cable or your own body. Gloves can help reduce the risk ...


5

The PCM controls charge rate on this vehicle. It monitors battery voltage and amperage flows to decide when to charge and when to rest. This is done as a fuel saving strategy. Some systems use a three step strategy: No charge, 13.5 and 14.4v. Some use a two step strategy. The voltage at the power socket should be correct minus a tenth or two of drop due ...


5

In the circuit that contains your starter relay there is a fuse, typically it is a 30amp fuse. Here is an image a Yamaha R1 starter relay fuse Depending on your model of motorcycle you will need to: Discover the location of your relay fuse Remove a plastic cover for the relay Possibly, remove a plastic cover for the fuse. Remove and Replace old fuse ...



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